It has been 50 years since Ezra Jack Keats introduced the world to young Peter, the little hand-painted boy who awakens to a fresh snowfall and sets out on a joyful errand.

"He picked up a handful of snow — and another, and still another. He packed it round and firm and put the snowball in his pocket for tomorrow. Then he went into his warm house.

"He told his mother all about his adventures while she took off his wet socks."

The sweet — and familiar — simplicity of Peter's wintry pursuits earned Keats' "The Snowy Day" immediate accolades from readers and reviewers alike, in addition to the 1963 Caldecott Medal and eventual placement on the New York Public Library's 100 Most Important Children's Books of the 20th Century.

When "The Snowy Day" debuted, few children's books characters looked like Peter, whom Keats painted as an African-American child. His skin color plays no role in the plot but was nonetheless noteworthy — and, for some, life changing.

"'The Snowy Day' represented the end of a long period where books for children were lily white," says Regina Hayes, president and publisher of Viking Children's Books. "If there were black characters, they were colored gray, and Ezra Keats really changed that."

Among the book's early fans was one Langston Hughes, who wrote in a letter addressed to Louise Crittenden (head of publicity for children's books at Viking Press from 1955 to 63): "'The Snowy Day' by Ezra Jack Keats is a perfectly charming little book. I wish I had some grandchildren to give it to. Yes I do!"

Keats, who died in 1983, once told the Minneapolis Star he received a letter from an elementary teacher who said that before she read "The Snowy Day" to her class, both her black and white students would use pink paint to represent themselves. After reading the story, the black students began using brown paint.

"It gives them a sense of belonging," Keats said at the time. "They are in books."

The aforementioned anecdote is included in the 50th anniversary edition of "The Snowy Day," which includes eight pages about the book's genesis and reception. Peter, we learn, was inspired by a set of photos Keats saw in a 1940 Life magazine of a little African-American boy receiving a vaccination shot.

"He cut it out and put it on his bulletin board … and had it gestating inside him for many years," says Deborah Pope, executive director of The Ezra Jack Keats Foundation. "I think he looked at this boy, and he saw himself. If you see the series of pictures, the boy is ebullient, glowing, happy, getting attention. And then he puts his arm out and gets the vaccine and looks back at the camera saying, 'You hurt me. How could you do that?'

"And I think that Ezra related to that. To the trust that children have and their willingness to reach out and all too often to the result that they're hurt," Pope says.

Keats was notoriously modest and had no idea his book would be as remarkable as it proved to be, Pope maintains.

"It's interesting," Pope says, "in hindsight, that he wouldn't know what his book would mean to the world, given the history of our country, given what was going on in 1962, given the social upheaval and all the ways society was erupting. But he was working in his own studio and working out of his own head, and to him, this was just a book about a child who has a day of absolute joy in the snow."

Which is, in part, why it resonated so deeply. Picture books, Pope contends, are a wonderful way to expose your children to different cultures.

"You want the spirit to be that this is just life, and it's a good book and a good story, and the child isn't being pounded over the head," she says. "And that's the gift you give your kid — the knowledge that it's a big, friendly world."

Through storybooks, parents can make a point to expose their children to characters and worlds that look quite different from their own friends and neighbors. Deborah Pope, executive director of The Ezra Jack Keats Foundation, offers some tips on diversifying your own collection.

• Ask your local librarian for recommendations. "Librarians are a breed of people we don't appreciate enough in this society," Pope says. "Especially children's librarians — they adore children and literature in a way that I don't think many of us can fathom. They are wonderful resources."

• Look at past Ezra Jack Keats award winners. The foundation bestows a new author award and a new illustrator award each year on selections that "portray the universal qualities of childhood, a strong and supportive family and the multicultural nature of our world."

• Find stories you love. "A good story has the spirit of life," says Pope. "It's not like taking medicine."

• Discuss the book. "Say, 'Oh my goodness, I've never seen anything like that. Have you?' Make it a real experience for the two of you. That's the way children learn."